Probably the best-remembered ad of all time was for the Apple Macintosh computer:
Here are two soft drink commercials that riff on previous TV commercial styles…
Greenpeace anti-fur commercial
Compilation of Greenpeace commercials
Seattle fish cleanup commercial – great idea, no embed tags. Here’s the link.
Anti-smoking – Just focus on the positive
Anchors of animation
Farley’s organic beer riffs on I Love Lucy